Friday, March 10, 2006

Apache Shale Web Framework

Apache Shale is a Java Server Faces based Web Application Framework from the Apache software foundation. Shale is talked of as the "heir" Apache struts framework. We all know that struts is the most used Java Web Framework so far. While shale is the successor of Struts, there is a significant departure of architecture from sturts to shale. Firstly, while struts is based on a monolithic Request Processor, Shale is set of fine-grained services that can be combined as needed to meet particular application needs. Secondly, while sturts can be integrated with Java Server Faces, Shale is built upon JSF. The major features of the Shale Framework are:

View Controller - Convenient mechanism to associate a "backing" Java class with each JavaServer Faces view (a JSF WebPage) in an application, with predefined event handers for events significant to an application developer.

Dialog Manager - Mechanism to define a "conversation" with a user that requires multiple HTTP requests to implement, modeled as a state diagram.

Application Manager - Traditional application wide front controller features that should be applied to every request.

Validation - Integration with the Jakarta Commons Validator Framework, supporting both client side and server side validations based on a single set of configured validation rules.

Remoting - Server side support for applications that employ AJAX (Asynchronous JavaScript and XML) style interactions.

Clay - An alternative to JSP where you define views in pure HTML, in a fashion similar to Tapestry and Facelets. An innovative sub-framework for supporting the configuration of reusable subtrees of JavaServer Faces components for customizable reuse.

Test Framework - Set of mock objects and JUnit test case base classes suitable for testing both the framework classes themselves, as well as application components built on top of the framework.

Java 5 Extensions - Optional add-on library that adds additional ease-of-use features for Shale applications that run on Java Standard Edition 5 (popularly known by its code name during development, "tiger").